1. Field of the Invention
The present invention generally relates to a micro mixer.
2. Description of Related Art
Various static mixers for mixing at least two or more types of fluids have been proposed. Static mixers are used in fine particle manufacturing by chemical reaction and crystallization. Among them, micro mixers in which the fluids to be mixed are supplied in the micro channels have been attracting attention.
Micro mixers have micro channels in which the micro channel width is in a range of 10 μm to 1000 μm. In the micro mixer, at least two types of fluids are mixed after being divided into minute flows by micro channel. In the micro mixer, the fluids are divided into minute flows and the fluid diffusion distance becomes shorter. Accordingly, the fluid mixing speed becomes faster. Thus, compared to the conventional static mixers, micro mixers can efficiently mix fluids in a small period of time.
As for the structure of micro mixers, for example, mixers having Y-shaped channels are well known. In such kind of mixers, the channel for the first fluid and the channel for the second fluid intersect to in an acute angle, i.e., Y-shaped, so as to form a merging channel. The fluids respectively supplied in the channels merge at the intersection point of channels in a state of laminar flow. After that, each fluid diffuses and mixes with each other.
In Patent Reference 1, a lamination micro mixer is disclosed. The disclosed lamination micro mixer includes a plate in which a micro channel for a to-be-mixed reactant A to flow therethrough is formed and a plate in which a micro channel for a to-be-mixed reactant B to flow therethrough is formed. Viewing from the above of the plates, the micro channels intersect to form an acute angle. Each of the fluids merges at the inlet of the mixing/reacting chamber.
As described above, in the mixers in which channels are arranged in a Y shape and the mixers in which micro channels are arranged in an acute angle, each of the fluids mixes in a laminar state. Therefore, each aforementioned mixer is suitable for mixing low viscosity fluids. However, in case of mixing high viscosity fluids or mixing fluids having large difference in viscosity, there is a problem that the contact area of fluids and shear force in the fluids may be reduced, and mixing efficiency may be decreased.